Attachment for microscopes



May 18,1926. v V C. H. BIERBALIM'l ATTACHMENT Fon MIcRoscoPEs Filed Deo.. 29, 1920 5 sheets-Sheet 1 May 18 1926.

C. H. BIRBAUM ATTACHMENT FOR M'IcRosoPEs Filed Dec. 29 1.920

3 Sheets-Sheet 3 Patented May 18, 1926.

Prihl'f FFEQE.

CHRISTGHER H. BIERBAUIVI, Ol* BUFFALO, NEW YGRK, ASSGNOR T0 AMERICAN SOCIETY OF MECHANICAL ENGINEERS, 0F NEW YORK, N. Y., A CORPORATON -OF NEW YORK.

ATTACHMENT FOR MICROSCOPES.

Application filed December 29, 1920.

The essential characteristics of all bearing alloys is a structure made up of alternately hard and relatively soft miscroscopic particles intimately mixed. The function of the hard particles or bearing crystals is to support the load and resist the wear. These bearing crystals should not be hard enough to prove distinctly abrasive to the journal surface. General experience shows that an extreme hardness of the bearing crystals is characterized byA an excessive wear of the journal. The function of the softer or more readily abraded crystals is that of being plastic and permitting the bearing crystals to adj ust themselves to surface requirements of the journal. These softer crystals are also more. readily abraded, and therefore wear slightly below the surface of the bearing crystals and thus form slight depres sions upon the bearing surface which serve for the retention of the lubricant.

The importance of a knowledge of the inicro-characteristics of alloys nas long been appreciated by investigators who have used the microscope in the study of alloys, but the only device heretofore employed for testing the relative hardness of the different crystals has been an ordinary needle point by which a scratch was made across the surface of the crystals to be tested, under as uniform a pressure as possible. rfhe part of the scratch through the soft crystals is deeper and therefore wider than the part through the hard crystals, and by measuring thc width of the cut trie relative hardness of the crystals is detcrn'iined. rThe results obtained with a needle are however unsatisfactory in that it cannot be ground as line and sharp as a jewel and its control is diflicult and irregular.

One of the objects of my invention is the provision of a convenient microscopic attachment which permits a nice and accurate adjustment of the scratching point or cutter and insures a reliable action and control thereof. V

A further object is to provide a mounting for the cutter which renders it extremely delicate and sensitive in action7 enabling it to follow the undulations or irregularities of the surface of the tested alloy.

The improved attachment, which I have vSerial No. 433,811.

named a cmicrocharactei, is mounted on the usual stage of a microscope. It comprises, in its general organization, a scratching point7 cutter or jewel carried by an arm or bracket and adapted to maire an incision across the surface of the alloy to be tested; a. carriage for thetested surface which is adjustable to bring ksaid surface in the optical axis of the microscope, and mechanism for slowly and regularly feeding the carriage in the proper direction to carry the test surface past said point. rlhe attachment also includes a delicate elastic mounting for the jewel point, as well as means for adjusting the mounting and its carrying arm to properly position the point.

ln the accompanying drawings:

Figure l is a perspective view of a micro scope equipped with the invention. Figure is a top plan view of the attachment removed from the microscope and showing the micrometer feed thrown out of gear` Figure 3 is a fragmentary sectional plan view of the attachment, showing the micrometer feed thrown into gear. Figure 4i is an enlarged transverse section on line flue, Fig. 2. Figure 5 is a fragmentary longitudinal section on line 5 5, 2, on an enlarged scale. Figure t5 is a vertical section, on an enlarged scale, of the means for raising and lowering the bearing of the suspenson bracket. Figure i' is an enlarged transverse section on line TJ?,

Q, on an enlarged scale. Figure 8 is an enlarged longitudinal section on line e-Qu 2, Figures 9 and l() are transverse sec tions on the correspondingly numbered lines in 2. Figure il is a perspective vice of the carrying spring of the cuttingT point. ligure 'lf2 is a greatly enlarged side elevation of the cutting point. Figure 13 is an end view thereof. Figure lll is a top plan view of a test-surface showing the cut pro duced by the instrument. Figure l5 is a fragmentary front elevation of the instrument. Figure 'i6 is a top plan view of the bearing of the suspension bracket. Figure i7 is a plan view of one of the holdingl jaws of the carriage.

Similar characters of reference indicate` corresponding parts throughout the several views.

Y [tM 1 Worin sini 111s 5l, 52 which s itolly hat enfl oA li le in the @ne 01"' these p11 eins thwise att Aiofizo the V11s worin sl f' movable to ig. 7. Abuttir of t g, this is i' 5 t0 roe 46 and provleln extent len ""1 Wheel el, 11s s e drawino e. sho` t 1? With O, for t 'the i reierrecl Cons L1 Llieering fin o in tl :ingr 11 its f ot bearing `t' th ls o `pressed 11 this traite wel es shown in nte sides of the rear end ot the pino - are shifting roeiers rillous-tomar) nd br llorV 'these ein shown 1" o 2 edge l:1

entiiz tege :1nd A11 opr 111 lngs. i

horizonti l rch 1s pre provide-1l at its her 19e 2 the nih ront

vin the preh or o ext ing a clam meinst the onde tuehinent is liaving ilnniin` :111 oeuler ZL; eron'ieter ses.

Stationen;T :rochariieter un suitable el inps for reit t the ste' across the de et the stage.

shown, eac ses a jaw L the s v2G carry ears e, as best showi h :1 1111 eroseo over 111e top or il 1n connection wit i1/:Mo

motion sel 111 the 111i sliepen and bly seeurin :endin which b v l i O rvu rail) posi ifi il D

ui of from fl in thia` the leihlj/ 1-ro- O sin'nl lich 91111511;

hemlie t pleite z in the 11'01'111 1d eee. o1- the to grasp between them in 1@osition irl a he owerd 111 tl s secondary slid ontnl jews or ho1 nier the outer e neil iii

11 S ft n l a S .e

rino' g away isey O t, heel 4:9, so es it l. dat-e chtierent-s 1 L11s purpose the shank s the inner 111111 oA i ulorui he inner behintlL Whie the pos1t1011 shown m is 1 re referat pivoted .1 wes the r s ed ele

s to hold fr diseonneetin This lever may be loch 1 tie 59 :1n/l ve rrespending parts o surlI vek lill

the pr ly to 1111 the 1os1t1 n shown G11 of th otherwisU ing ens),`

e' if; e

y by 21 s 1i of stair iltting p 1 sWin m' left is 9,

to the fece Ws with a ich .l egews.

, is pro vin s are adjustable oooh other to 5113001111110 lll plates, e d for tl i :are ret fr gear therewith, as s ageins 1 lever t' pm rom the het shown 1n 11e' wheel `ed l o. piece 0r sur fl these 1:1 ree end er (3V rh salti plate an( :zel

(l the '1101'111 shaft 111 Beer] er si .1 he secondary ruled with e scale Carrie-:l by thi spaced horiz eloffel,Y

.ai i" f, iss or other suitable 11i cemento en th horizontal tor Withth 21 brl tending eo wor J s). 111- otl shipper bracket 54 and having knob 5T to 111g 1t. lever t Worin th 1.1051111011 by :1 stud 58 'ver snaps on reach 1.1'

is @arranged One of primary slide, 1s its f beure toil the "Worin-sl esoonthnping Fi nion is secured to the lower end pid V the 1...'3 1 '-`1 surmise. nereinoebe o but that eriib lows:

l1e 2l ot to the led in ng: a 111111011 4-2 11 e gear rook 43 on the ly e esh

n in

:1r 2) :incl the 'freir 1 1 rimer (love enerl Lage and e L side o,

:1 with e transhis bar 1s proerably, the

ion, pret :1s toi f ot the sL With o 1 fast 111e 2li, 21s show in the slide-bar 9' knob 35 :it its slide Vicent longltuchnal Pref 1e rapid feed e011- iournzi fi 1de 38, as shown i he spindle 11511111111; 11 knob trriot i tigo( leflL Qeratin seontlory slide de with :1 ciovetzul esateno e of the .ASIS it, is constructed Movable trensvesel side groove 30 which receives a cor rely. nary slide 28 to more o ssn-'ise 'thereo 1e tes 1111s carnage 11111 oons the con de 1s aetneted by a oinion gesti prn e011, 1s a 5 and s eqinpped with both ra eviees.

spindle ll 'nel lary sl se and ero 1Wise thereof, is led at one enel b ed on its inner -tenon 3l on tra.

)il journa le-b y prow'led With seele and res1 th A1 its under f'h1eh enge..

uid

feed (l.

Wit

econ( for t ioned. ppropria 01.1111 in the dr engtl ic rlhis sl enrrzetl by its end bar 29 9.1

e1 horizontal rack 33 1 the pi @n their ad i l S?, al on r-.e 1i-lier per ies

ioiinted on the stage to more lengthwi lov Cer tending l 30 sl de 2S prov renie Qfl.

de o rl`h1s spinfl and having an o 1 preferob D a \f'ern1er iounte lenothn'i" shown in Fi eh mesi L :1nd

ore 111e ide With

:ter s1 per end.. edges, sand la" n provic e priinery Y eh of th Y,

m `for t1 "l the )loye Verse Carryin vi .Il se ge grooif'e 39 v. 30 on the 11D secondary slitle and slow vt1 Whi y slide, as shown seeondai" 15S Corrieri bj; the 1n .110.7

past Wine caused to inove by t 11 bearings L16, l? prosifle t 79 secured to the sp s a crank 45 4&5 onrnaled i the rear :11o Cerwin 'Qthis shaft h shaft tessere Rigidly mounted the 'iront incini r ot the fixed traine 2iis a standard 70 cariynig a vertically/adjusjtable slide 7l which is suitably zguided on the standard and which may be adjusted by a pinion Z2 nieshii with a vertical rachr 73 secured to said e ineinber, as shown in This pinion is carried by a transverse operating shaft la@ journaled Yon said slide 7l. Carried by this slide is an up gght l'iearing` or sleeve T5 which receives a pindle 76 having@` a 'lf-head 77 which normally rests upon said bearing in a. position parallel with the secondary carriageslide 38, in which position. it is retained by a stop `face 78 torined by the upper end of the vertical slide 7l which entends above the top oi" the bearing 'Z5 tor this purpose. 'lhis '-head may be turned at right angles te its normal. position, for a purpose hereii'iaitter niore fully described, by raising' it above the upper end ot the slide 7l and then giving the lihcad a quarter turn and allowing it to drop into a locking recess T9 in the upper end or" said slide, as shown in Fiss. fiand 1G. The spindle 7G is loosely seated in its bearing to perinit ot this lifting and releasing action ot the T-head.

Pivoted on an upright stud 8O at one end ot said T-head is a horizontally adjustable bracket 8l et substantially -shape which carries the mounting; of the cutting point. Une end ot the cross bar ot this braclret is titted upon the pivot-stud SO while its other end carries a 'transverse yolre 82 which receives the adjacent end oi the T-head 7'?. interposed between one or the yoke-jaws and said mhead is a spring 83, while in the opposite jaw threaded an adjusting ser-l v which bears against the adjacent side of the 'Tf-head and serves to adj ust the cross bar oi'V the bracket 8l laterally' with reference to the Ei-head, tl'iereby cl'iangginp' thel position oit the body or main arin et the brarch'et cordingly.

M nted at the free end ot bracl-et vche or carrier having; an upright cajiable of of-:cillatinp,` in a bearing' This yolre is provided with a iaterally-ez;'ending arin S8 the outer rear erin tbereot, a delicate s crabiy a steel blade, in the tree enl o? whi h the cutti point (Si) is inou L l best shown in i1 les 8 and ll. ln its preferred 'torni this spring tapers evenly tovard the cutting point.

@ne or incre small weights are rpon a stud 95 at the 'trout end oi the @l directly over the cutting' point to cause the latter te eserthe desired pressure upr'iu the test'-, face elastic mounting, the point is mused to bear yieldably upon the test-surce, allowing the point to rise and ta l it s traversed by crystals oi diii'erent degrees hardness. Provision is also niade forregulatinfay tlc tension of the spring 93, the device shown in the drawings consisting' of a vertice screw 9G arranged in an opening oit the leve and bearing upon the spring; at av suitable distance .troniA its point et attachment thereto,

it suitable spirit level 9T is carried by the ever, preferably by its rear arin, as shown, o facilitate the adjustment oi the jewel- .wwinge' Si?) to a horizontal position, which is ential to obtain accurate results. llo protect the delicate jewel point and its spring, a suitable guard 98 may be extended around the `front and along the sides ot the lever 91.

The cutting point inay be et any appropriate construction, but it is important that it shallbe extremely tine and sharp, hard and tough, and oit the proper shape and proportions. lt has been found that a jewel point cut :troni artificial white sapphire. (fused lQOB) is very satisfactory and meets all requirements. lt has also been found that special advantages are possessed by a point having the shape of a corner of a cube, as shown in Figs. l2 and 13, and accurately mounted so that the three facets 99 inakc equal angles with the test-surface, 7ith one edge or the cube in the direct line or motion et that surface. rlhe leading or advance edge l0() of the cube and the line ot cut `form an angle of 35.26 degrees (the angle of incision), which insures that the normal pressure upon a crvstai is always greater than the transverse pull, thus completely el'nninatinv the objectionable tearing effects of a sharp conical point. This forni ot the cutting` point has the further advantage that its bach tace is inclined and not abrupt, allowing the jjj-sint to slide troni a hard to a sott crystal without a junip or ar and givinga more accurate reading.

Figure 13 presents an end view of 'the preferred jewel point, showing the three facets ground at an angle of 5dr-.73 degrees to the axis, each facet beingground after i: oi

ln its original form the jewel is a small cylllO inder, say 0.022 inches in diameter and three thirty-seconds of an inch long, and the point is ground and tested before the jewel is mounted. ihe mountingY is preferablyA done by accurately clamping` bot-h the jewel and the jewel spring in a jigor fixture while in the field of vthe microscope. it heavy solution of specially refined shellac is then applied to the point on the lower side of the spring and permitted to harden. The spring is then removed from the and a small amount ot' this shellao is applied to the j en'el on the upper side of the spring. After this has hardened the excessive top length of the jewel is ground olf in order to reduce its weight to an absolute minimum. Alcohol should therefore never be used in cleaning the point, yline being` the most desirable solvent to employ.

ln the use of the improved attachment, after applying it to the stage of the microscope, as hereinbefore describen, the sns )ension br'L clret 8l with the said point and other parts carried by it, is swung aside, as shown by dotted lines in Fig. r,the glass plate with the test-surface of alloy fastenec thereto is then placed between the jaws (il, ('2, of the carriage, where it is securely held by the spring-pressed linger rllhe cz'irriage is then moved longitudinally to its initial position by turningv the spindlelmob The carriage is nent adjusted crosswise of the stage by the spindle knob to bring the test-suriace in the optical axis of the micro scope. "llhen the suspension bracket Sl is returned to its neri ral position, as shown by full lines in the drawings, and 'the bracket and the jewel-point lever 0l arc adjusted by means of the screws rift and "t accurately position said lever parallel with the longitudinal line of travel of the carriage and bring' the jewel-point in the focal axis. rThe carri is then adranced lengthwise of the stage, by the worm feed hereinbefore described, thus feedingthe test-surface past the jewel point which makes an incision across it, as shown at 10i T1ig. 14;. To

Y-, in n insure corroborative results, the test-surface should be moved past the jewel-point at n. slow nd constant rate, and this requirement is well met by worm gearing. Any other suitable feed mechanism may however he employed for this purpose, and l do not therefore wish to be limited to the particular gearing herein shown and described. More over, the rate of travel of the carriage should be so slow that no additional indentation is `lfl'ected by stopping` of the test surface. rt the same time, the cutting point should be held in such a manner that while passing from one crystal of the test surface into another, the point can instantly take a. new position without having'to overcome excessive inertia of moving parts. Accordingly, the jewel itself isreduced inweight as much as possible and carried by an elastic mounting of the character described, which gives the point the requisite sensitiveness and delicacy of action to obtain the desired results.

lt is desirable to lubricate the test-surfaces. Sfandard optical cedar oil having' specific gravity of 0.976 at lo degrees cent. has been found very satisfactory for this purpose. rllhis oil may be left upon the riace while making the necessary measurements, after which the oil may be left to dry upon the specimen and so form an effective coating` against corrosion. The jewel point should be kept clean and should be cleaned immediately after use, since a small amount of oil dried on alone or in connection with other material may produce very erratic and un accountable results, even though this dried` on material be so small as to be barely visible. l have found that elderberry pith Wetted with iiylol is a very desirable material for cleaning,1 the jewel point. rllhis pith is also very suitable for wiping oli' the testsnrfaces after a cut has been made, since a freshly cut surface of this niaterial'will not scratch or mar the test-surfaces and will carry away thc loose chips made by the cut. l-Figure lil illustrates a micro-cut 1.0i made by the microcharacter across a portion of a fused tin oxide crystal en'ibedded in bronze. The difference in the width of the cut indicates a dilierence in hardness between the two materials. rllhis is but ai example of a test.

`The instrument is adapted for a wide range of such test work, including not only the Various bearing` alloys, but also all the steels suitable for journals, whether soft or hardened, as veli as any other material consisting of microscopic particles of varyingl hardness.

it is obvious that this improved instru- -nt or attachmei'it n'iajjf'be modified in within the scope the apand l do not therefore wish 'm as my invention:

'lfhe combination with the stage of a nncroscope, et an attachn'ient of the cnaracter described, comprising" a frame having to frame,

means foi. e'

.-nried by sait. y

' ted on said bracket, and a car dingy; primary slide guided on more c J scratchi resaave microscope-stage, a bracliet carried by said frame, a cutter mounted on said bracket, an L-shaped primary slide guided on the transverse member of said frame to move crosswise of the stage, a secondary slide guided on the longitudinal member et' said primmjf,v slide to move lengthwise of the stage and having a holder for a test-surface, means t'or adjusting said primary slide, and 'feed' mechanism for said secondary slide.

3. A microscope attachment, comprising a carriage iior a test-surface, a standard, a head rotatably mounted on said standard, a bracket mounted on said head, and a cutter carried by sait. bracket, said standard having a stop for retaining said head in normal position and a locking,` notch for holding the head in its inoperative position.

el.. A. microscope attachment, comprising a carriage tor a test-surface, a standard, head rotatably mounted on said standard, a bracket fulcrumed at one end on said head to swingI horizontally thereon, means for later ally adjustingl the free end of said bracket on said head, and a cutter carried by said bracket.

5. A microscope attaclunent, comprising a carriage for a test-surface, a standard, a head rotatably mounted on said standard, a bracket provided at its inner end with a cross bar, said cross bar being;` pivot/ed at one end to said head and provided at its opposite end with a yoke emb acing said head, an adjusting screw carried by said yoke and en raging said head, and a cutter carried by said bracket.

6. ln a microscope attachment ot the character describedl` a vertically-swinging carryine' member, a. yieldable member attached to said carrying' men'iber and carrying' a cutter point,` and a spirit level mounted on said carrying` member.

'i'. A mi Jroscopc attachment, comprising a carriage Jfor the test-surface, a support 0verhanging;- said carriage, al member swiveled on said support, a vertically-swinging lever `fulcrumed on said swiveling member,'and a cutting point carried by said lever.

8. A. microscope attachment, comprising a carriage for the test-surface, a support overhar'ging the said carriage, a member swiveied on said support, means 'for adjusting said swiveling member on said support, a verti'ally-swinging lever ulcrumed on said swivelingr member, and a cutting` point carried by said lever.

9. A microscope attachment, comprising` a carriage for the test-surface, a support overhanging' said carriage, a member swiveled on said support and having an adjusting arm, an adjusting device `for said arm carried by said support, and a cutting point carried by said lever.

lO. A microscope attachment, comprising a carriage for a test-surface, a bracket overu hanging said carriage and adjustable in a substantially horizontal plane relatively to the carriage, a member swiveled on said bracket, means for adjusting said swiveling member, a vertically-swinging lever ulcrumed on said svviveling member, and a cutting point carried by said lever.

ll. A microscope atachment, comprising a carriage for a test-surface, a bracket overhanging' said carriage and adjustable both in vertical and horizontal planes relatively to said carriage, a member mounted to swivel horizontally on said bracket, a vertically-swinging` lever ulcrumed on said swiveling-member, and a cutting point car ried bv said lever.

12.111 a microscope attachment of the character described, a carriage for a testsurface, combined with a cutting point having the shape o1 the corner of a cube, the three facets of the point making equal. angles with the test-surface and one edge of the point facing the direct line of travel of said carriage.

CHRSTOPHER H. BIERBAUM. 

